1. Field of the Invention
The present invention relates generally to camera devices and, in particular, to a camera device suitable to be used as an on-board camera attached to a vehicle to improve the convenience and safety thereof.
2. Description of the Related Art
In order to improve the convenience and safety of an automobile, a camera device has been provide that is mounted on a vehicle body to visually recognize the periphery thereof by use of a monitor installed near a cockpit. The camera devices of this type have a generally rectangular housing in which an image pickup lens and an image pickup element are incorporated. This housing is built in or mounted on a rear door, a side mirror, a front spoiler or the like of the vehicle body so as to allow the image pickup lens to face the outside. The camera device as mentioned above can view the periphery of the vehicle body as a driver's blind spot to improve safety and convenience.
Incidentally, it is often difficult for the camera device of this type to blend in with the exterior design of an automobile. In addition, it is desirable for the camera device to be exteriorly inconspicuous as much as possible. It is not preferable in preventing damage or in preventing the image pickup lens from getting dirt that the housing is significantly exposed to the exterior. This is because a risk increases in which the housing comes into contact with the outside during vehicle wash, during opening or closing of a door, during traveling or during parking. Thus, the camera device is desired to be further downsized.
A camera device used as an on-board camera is formed generally rectangular and includes a housing in which an image pickup lens is incorporated; and a substrate on which an image pickup element such as a CCD (Charge Coupled Devise) is mounted. In addition, the camera device is formed such that the substrate is secured to the inside of the housing in such a manner that the image pickup element is opposed to the image pickup lens. The housing is composed of upper and lower halves. The substrate is secured to inside of one of the halves and then the one half is joined to the other. The securing of the substrate to the one half is performed using an adhesive or screws.
The securing of the substrate to the one of halves is needed to provide significant strength to hold the respective positions of the image pickup lens and the image pickup element. In particular, the camera device used as an on-board camera needs resistance to shocks during opening and closing of a door and during traveling. However, if securing is performed using an adhesive, it is necessary to ensure an adhesive application area over the full periphery of the substrate, i.e., along the external edge thereof. This necessity leads to the increased size of the substrate taking into account the mount area of the image pickup element, etc. In a case of screwing the substrate to the one half, if a plurality of screw insertion areas are provided, the substrate is similarly increased in size. The increased size of the substrate will undesirably increase the size of the housing. See Japanese Patent Laid-open No. 2007-225991.